Direct travel mechanism for electrical reactors



2 Sheets-Sheet 1 J. CARNAZZA ,M SQIL DIRECT TRAVEL MECHANISM FOR ELECTRICAL REAGTORS L L N En A l/dl/ wwy@ Q1 JA A Nov. 15, 1966 Filed May 24, 1965 J. CARNAZZA Nov. 15, 1966 DIRECT TRAVEL MECHANISM FOR ELECTRICAL REACTORS 2 Sheets-Sheet 2 Filed May 24l 1965 fifi/:iii

United States Patent eO 3,286,140 DIRECT TRAVEL MECHANISM FOR ELECTRICAL REACTORS Joseph Carnazza, Broklyn,-N.Y., assigner to JFD Electronics Corporation, Brooklyn,.N.Y. v

Filed May.24,;1965,1Ser. No. 458,065 7 Claims. 4(Cl. 317249 This invention relates to variable velectricalreactors in general and more specifically relates to anovel direct travel mechanism, wherein movement `of theadjustable ,re-

actor element is limited-to translation as a result .of rotatcircuits yare usually, of necessity, constructed of elementswhich are positioned very close to oneI another. -Slight changes in the spacing between elementsV willlcause significant changes in reactances athigh frequencies. Thus, it becomes necessary to assurethatthefelements of the e reactor remain in adjusted position'-even under conditions of shock or vibration.

Further, it is desirable that the y rate vof reactancechange be more orless uniform as theadjusting. member'is operated and for practical reasons itis necessary that the possibility of reversal beeliminated. Thatis, as theiadjusting member Ais operated in a. direction to incre-ase re? actance value this value shouldV continuously increase without any decreases taking place, the converse being true for operation to decrease. reactance.

It has been found advantageous toutilize -a rotatable adjusting member, such as a'screw having all'butthe'top of itshead enclose-d, in that a relatively large angular movement produces a relativelyhsmall axial movement. However, it has been found that when the adjustableelement of the reactor is permitted to rotatevas it is'being translated, any. eccentricity between the adjustable element and its cooperating stationary element results in unpredictable variations in the rate of reactance changefor a given rotation of the adjusting member. IV-Ience, the necessity for limiting movement of the adjustable member to translational motion. f

Accordingly, a primary object of this invention is to provide a novel operating means for translating without rotating an adjustable reactor elementthrough rotation of an adjusting member.

Another object of this invention is to provide a novel direct travel mechanism for reactor elements that is relatively inexpensive.

Still another object of this invention is to provide a direct travel mechanism for trimmer or tuning capacitors which materially simplifies assembly.

A further object of this invention is to provide a novel direct Itravel mechanism for -trimmer capacitors which provides good electrical contact between the bushing capacitor and a movable piston.

A still further object of this invention is to provide a novel direct travel mechanism for trimmer capacitors which provides adjustment holding torques and is free of backlash.

These as well as other objects of this invention will become readily apparent after reading the following description of the accompanying drawings in which:

FIGURE 1 is a. longitudinal cross section of a trimmer capacitor constructed in accordance with the teachings of the instant invention.

3,286,140 Patented Nov. 15, 1966 "ice ,FIGURES Zand 3 are cross sectionstaken through lines 2-2 and 3 3, respectively, of FIGURE l looking in the directions ofthe respective arrows.

FIGURE 4 is an exploded perspective of the capacitor illustrated in FIGURE l.

lNow referring to the figures. vElectrical reactor or capacitor 10 includes hollow glass cylinder 11 constituting ,asl a means for fixedly securing hollow bushing 14 to form f 11. That is, bushing 14is provided ata point intermediyatevtheends thereof with annular ange 15 dividing bushing `14 into an internal portion 16 and an external portion `17. Internal portion 16\ is cylindrical and 'is disposed withvin form 11.. between internalportionl and flange 15, concentrically positions the external surface of internal portion 1'6 in 20' Bushing shoulder 18, locatedl at the junction spaced k.relation with theninterior surface of form 11.

"Solder bead .19, formed be'tweenco'nductiveband 13 and 'ffii-inge 15, mechanicallysecuresbushing 14v to dielectric form` 11.

Cupv shaped piston 20, constituting theadjustable element of'reactor 1 0, isdisposed withinform 11 and is closel'yffitte'd withrespect to the interior surface thereof.

Alisto'rr20 is so ypositioned thatthe skirt `portion thereof telescopes` over theinternal portion 1.6 of'bushing 14.

Axially extending post 21 at one end of screw 22 extends through 'aperturek23' in thebott-om ofl piston 20l with a solderconnectionbetween piston 20and post 21 mechanically' and Yelectrically securing piston 20 to screw 22.

Screw 22 is provided with an exterior flattened portion 24 Whichextends axiallyfrom the part21 to a point 24a justshorltof lthe end of they screw. .With the ,body

of screw 22 extending'through D-shaped aperture 25 in `washer 26, screw 22 may,A move axiallywith respect to washer`26 but is restricted against nuts 31,32 for reasons 35 while diametrically opposed radially Vextending ears 31a, 31a vare entered into the relatively shallow slots' 36, 36 of rotatable bushing 35. The end of bushing 35 is peened over. at S'Sator retain nut 31Mmounted to rotatable bushing 35. Bushing 35 is provided with an axially extending cylindrical bore which is closely fitted to the exterior of screw 22while the cylindrical exterior surface 35a of *bushing 35 is closely fitted to the interior surface of fixed bushing 14. Bowed spring washer 38, disposed Within xed bushing 14 and surrounding rotatable bushing 35, bears against interior shoulder 14a of bushing 14 and exterior shoulder 35h of bushing 35.

O-ri'ng gasket 383', disposed within the annular groove 41 in surface 35a, acts as a seal between the stationary and movable bushing 14, 35. Groove 41 is located at the end of rotatable bushing 35 remote from the enlarged end 42 thereof containing slots 34 and 36. The end of bushing 315 remote fr-om portion 42 is closed and is provided with slot 43 for receiving an adjusting tool such as a screwdriver.

The portion 17 Aof stationary bushing 14 disposed exteriorly of dielectric form 11 is provided with a threaded exterior surface to receive nut means for mechanically securing capacitor 10 to a mounting surface and also for making electrical connections to bushing 14.

In operation rotation of bushing 35 relative to bushing 14 is effective to rotate torque nuts 31, 32 relative to screw 22. Since screw 22 is maintained against rotation by virtue of its :flat surface 24 cooperating with the flat bound-ary portion of aperture 25 in washer 26, screw 22 is limited to axial motion. This motion of screw 22 causes piston 20 to move along the axis of dielectric f-orm 11 without any relative rotation between pist-on 20 and form 11.

INuts 31, 32 in combination with spring 33 constitute a torque imparting means which prevents backlash and maintains a predetermined torque on screw 22 to prevent its accidental rotation with respect to rotatable bushing 35. Bowed spring washer 38 supplies a friction force which prevents accidental rotation of bushing 35 relatively to bushing 14. Thus, it is seen that the adjustable element 20 of electrical reactor 10 is caused to move axially without rotation whenever adjusting member 35- is rotated.

Although there has been describe-d a preferred embodiment of this novel invention, many variations and modifications will now'be apparent to those skilled in the art. Therefore, thisinvention is to be limited, not by the specific disclosure herein, but only by the appending claims.

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows: 1. An electrical reactor including a support, an adjustable element, an adjusting member, first means mounting said member for rotationA about an axis relative to said support, second means connecting said element to said member for axial movement relative to said support as said member is rotated about said axis while maintaining said element against rotation, said member including a tubular section, said element having a cup shape for telescoping over said .tubular section, said second means including first and second cooperating sections in threaded engagement, said first section being rotated by said member, saidsecond section being interposed between said first section land said element, said first means including a tubular bushing wherein said member is disposed, said member having a formation constructed-and positioned for engagement by a tool for rotating said member, said formation disposed within the confines of said bushing, said member being `tubular and being closed at a first end thereof, said formation being at said first end, a screw constituting said second section, a nut means constituting said first section mounted to said member at a second end thereof, said nut means including a first and a second nut mounted to said screw andspaced along the length thereof, a loaded spring means mounted to said screw, said spring means positioned between and bearing against said first and said second nuts, a bowed spring washer element sur-rounding said member and bearing against said member and said bushing.

2. An electrical reactor as setforth in claim 1 in which i there is a sealing means interposed between the exterior l of said member and the interior of said bushing.

3. An electrical reactor as setforth in claim 1 in which the support is tubular and surrounds theelernent, said bushing having an interior part within said support with said element telescoped over said interior part.

4. An electrical reactor as set forth in claim 3 in which the bushing includes another part disposed outside the supportand the first end of the member is surrounded 'by said another part.

5. An electrical reactor as set forth in claim 4 in which there is a sealing means interposed between the exterior of said member Aand the interior of said bushing.

6. An electrical reactor including a support, an adjustable elemen-t, van adjusting member, first means mounting said member for rotation about an axis relative to said support; second means connecting said element to said member for axial movement relative to said support as said member is rotated about said axis while maintaining said element against rotation, said member including a tubular section, said element having a cup shape for telescoping over saidtubular section, said second means including first and second cooperating sections in threaded engagement, said vfirst section being rotated by said member, said second section being interposed between said first section and said element, said rst means including a tubular bushing wherein said member is disposed, said member having a formation constructed and positioned for engagement by -a tool for rotating said member, said formation disposed within the confines of said bushing, said member being tubular and being closed at a first end thereof, a screw constituting said second section, a nut means constituting said first section mounted to said member at a second end thereof, said screw being provided with an axially extending flat surface coextensive with threaded portions of said screw, addi-tional means mounted to said support and defining an aperture through which said screw is axially movable, said addition-al means having a straight section defining said aperture with a shapecomple'mentary to said flat surface, said straight section and said flat surface cooperating to prevent rotation of said screw.

7. An electrical reactor as setforth in claim 6 in which said nut means includes a first and a secondnut mounted to said screw and spaced along the length thereof, a loaded spring means mounted to said screw, said spring means positioned between and bearing against said first and said second nuts.

References Cited by the Examiner UNITED STATES PATENTS 2,984,776 5/ 1961 Barnes S17-249 3,026,659 9/1965 `Goodman 317-249 LEWIS H. MYERS, Primary Examiner. ROBERT K. SCHAEFER, Examiner. E. GOLDBERG, Assistant Examiner. 

6. AN ELECTRICAL REACTOR INCLUDING A SUPPORT, AN ADJUSTABLE ELEMENT, AN ADJUSTING MEMBER,FIRST MEANS MOUNTED SAID MEMBER FOR ROTATION ABOUT AN AXIS RELATIVE TO SAID SUPPORT; SECOND MEANS CONNECTING SAID ELEMENT TO SAID MEMBER FOR AXIAL MOVEMENT RELATIVE TO SAID SUPPORT AS SAID MEMBER IS ROTATED ABOUT SAID AXIS WHILE MAINTAINING SAID ELEMENT AGAINST ROTATION,SAID MEMBER INCLUDING A TUBULAR SECTION, SAID ELEMENT HAVING A CUP SHAPE FOR TELESCOPING OVER SAID TUBULAR SECTION, SAID SEECOND MEANS INCLUDING FIRST AND SECOND COOPERATING SECTIONS IN THREADED ENGAGEMENT, SAID FIRST SECTION BEING ROTATED BY SAID MEMBER, SAID SECOND SECTION BEING INTERPOSED BETWEEN SAID FIRST SECTION AND SAID ELEMENT, SAID FIRST MEANS INCLUDING A TUBULAR BUSHING WHEREIN SAID MEMBER IS DISPOSED ,SAID MEMBER HAVING A FORMATION CONSTRUCTED AND POSITIONED FOR ENGAGEMENT BY A TOOL FOR ROTATING SAID MEMBER, SAID FORMATION DISPOSED WITHIN THE CONFINES OF SAID BUSHING, SAID MEMBER BEING TUBULAR AND BEING CLOSED AT A FIRST END THEREOF, A SCREW CONSTITUTING SAID SECOND SECTION, A NUT MEANS CONSTITUTING SAID FIRST SECTION MOUNTED TO SAID MEMBER AT A SECOND END THEREOF, SAID SCREW BEING PROVIDED WITH AN AXIALLY EXTENDING FLAT SURFACE COEXTENSIVE WITH THREADED PORTIONS OF SAID SCREW, ADDITIONAL MEANS MOUNTED TO SAID SUPPORT AND DEFINING AN APERTURE THROUGH WHICH SAID SCREW IS AXIALLY MOVABLE,SAID ADDITIONAL MEANS HAVING A STRAIGHT SECTION DEFINING SAID APERTURE WITH A SHAPE COMPLEMENTARY TO SAID FLAT SURFACE SAID FLAT SURFACE, SAID SECTION AND SAID FLAT SURFACE COOPERATING TO PREVENT ROTATION OF SAID SCREW. 